Ground monitoring

A team of US scientists are developing a wireless sensor designed to warn against geotechnical hazards such as earthquakes, landslides, and floods.

Tarek Abdoun, the assistant professor of civil and environmental engineering at Rensselaer Polytechnic Institute, is leading a team of scientists to develop a wireless sensor designed to warn against geotechnical hazards such as earthquakes, landslides, and floods.

‘Recent advances in sensors and wireless networking technologies provide opportunities for new ways to detect and assess the impact of natural disasters,’ said Abdoun, who is also associate director of Rensselaer’s Geotechnical Centrifuge Research Center.

‘The new system is designed to enable a better understanding of ground failure mechanisms and has the potential to significantly reduce losses from natural disasters.’

Abdoun describes the design as a long rope about one inch in diameter consisting of various sensors that are packed into polyvinyl chloride (PVC) piping. The system is water-resistant and can be inserted into the ground.

The sensor system uses fibre-optic and micro-electro-mechanical-system (MEMS) technologies to simultaneously measure key indicators of impending ground failure – ground deformation and soil acceleration. Each sensor is connected to a wireless node to enable real-time monitoring, as well as allow for a remote sensor configuration.

‘Real-time monitoring would allow for early detection and warning of geotechnical hazards, such as landslides, and help facilitate evacuations,’ said Abdoun.

According to Abdoun, real-time remote monitoring could replace manual sensors used by many state and federal agencies and eliminate the need to physically visit each site to take measurements and readings. The traditional manual systems provide limited monitoring capability – sensing acceleration or deformation readings, not both – and prove to be expensive, said Abdoun.

Initial estimates indicate the new prototype would cost less than one-tenth of traditional sensors.

The US Army Corps of Engineers and California’s Department of Transportation are sponsoring the field implementation effort of Rensselaer’s new system at four different sites.

The new system was recently tested at the National Research Institute for Earth Science and Disaster Prevention in Tsukuba, Japan, home of the world’s largest shake table for earthquake simulation. ‘Our initial test results are very promising,’ said Abdoun.

The research team, including Alhussein Abouzeid, assistant professor of electrical, computer, and systems engineering, and Mourad Zeghal, assistant professor of civil and environmental engineering at Rensselaer, also plans to use the data to create computer-generated model simulations for research and education.

The team’s work was recently featured in the September 2004 edition of Civil Engineering, the magazine of the American Society of Civil Engineers. It is funded in part by the US National Science Foundation.